1. Statement of the Technical Field
The present invention relates to the radio frequency identification (RFID) and more particularly to RFID object tracking.
2. Description of the Related Art
Conventional object tracking can range from ordinary inventory tracking to admissions ticket processing. For instance, in the context of inventory, object tracking can entail cataloging types, variations and quantities of physical items so as to know how much of any one physical item is present in inventory at any given time. Similarly, in the context of admissions ticket processing, object tracking can entail cataloging categories of admissions criteria and the like. Where object levels, such as inventory items or distributed tickets remain generally low and lack substantial variety and diversity from item to item, a conventional object tracking system can include a mere pencil and paper tracking method. In contrast, where object levels are significant and diverse in nature, technologically advanced methods can be employed. Once such technologically advance method can include bar code labeling and tracking systems.
The prototypical bar code based inventory tracking system includes a selection of bar codes which are affixed to the physical items to be tracked. In the case of a two-dimensional bar code, a sufficient amount of item information can be encoded into the bar code and read by a bar code reader through optical means such as a laser. In the case of a three-dimensional bar code, a vast amount of item information can be encoded in the bar code. In both cases, individual items in inventory can be tracked on an individual basis through the individual scanning of each respective bar code label.
While bar code based object tracking systems have proven to be highly effective in regard to efficiency and cost when compared to conventional pencil and paper tracking systems, bar code based inventory tracking systems remain deficient in their own regard. More specifically, to track a collection of items always will require the individual handling of each item during which time the bar code of the individually handled item can be scanned with the bar code reader. For small collections, the individual handling of an item can be of little consequence. For high volume applications, however, bar code scanning lacks a required level of efficiency and speed.
In respect to high volume applications, RFID techniques have been employed in lieu of bar code techniques principally because RFID techniques do not require the individual handling of an item during the object tracking process. Typical high volume applications include the processing of vehicles through a toll booth, security access cards and inventory control systems. Because the individual handling of an item is not required in an RFID based system, the tracking of objects in an RFID object tracking system further can be performed without the knowledge or explicit consent of the object, or the person in control of the object.
RFID is an area of automatic identification that has quietly been gaining momentum in recent years and is now being seen as a radical means of enhancing data handling processes, complimentary in many ways to other data capture technologies such bar coding. The object of any RFID system is to carry data in suitable transponders, generally known as tags, and to retrieve data, by machine-readable means, at a suitable time and place to satisfy particular application needs. Data within a tag may provide identification for an item in manufacture, goods in transit, a location, the identity of a vehicle, an animal or individual. By including additional data the prospect is provided for supporting applications through item specific information or instructions immediately available on reading the tag.
An RFID object tracking system requires, in addition to tags, a means of reading or interrogating the tags and some means of communicating the data to a host computer or information management system. In this respect, an RFID object tracking system also can include a facility for programming data into the tags. Notably, the tags can be active and powered in nature, or passive and unpowered in nature. Communication of data between tags and a reader can be by wireless communication. Two methods distinguish and categorize RFID object tracking systems, one based upon close proximity electromagnetic or inductive coupling and one based upon propagating electromagnetic waves. Coupling is via ‘antenna’ structures forming an integral feature in both tags and readers. While the term antenna is generally considered more appropriate for propagating systems it is also loosely applied to inductive systems.
RFID systems can be roughly grouped into four categories: electronic article surveillance (EAS) systems, portable data capture systems, networked systems and positioning systems. EAS systems typically involve a one bit system used to sense the presence or absence of an item. Portable data capture systems, by comparison, can be characterized by the use of portable data terminals with integral RFID readers and can be used in applications where a high degree of variability in sourcing required data from tagged items may be exhibited. Networked systems applications can generally be characterized by fixed position readers deployed within a given site and connected directly to a networked information management system. The transponders are positioned on moving or moveable items, or people, depending upon application. Finally, positioning systems use transponders to facilitate automated location and navigation support for guided vehicles.
Potential applications for RFID may be identified in virtually every sector of industry, commerce and services where data is to be collected. The attributes of RFID are complimentary to other data capture technologies and thus able to satisfy particular application requirements that cannot be adequately accommodate by alternative technologies. Principal areas of application for RFID that can be currently identified include: transportation and logistics, manufacturing and processing, and security. A range of miscellaneous applications further can be distinguished, including animal tagging, waste management, time and attendance, postal tracking, airline baggage reconciliation, and road toll management.
Despite many of the apparent advantages of RFID technology, deficiencies remain for some potential applications. Specifically, while RFID technology can be effective for garden variety inventory tracking, or for high speed vehicle logging, RFID technology heretofore has not been applied to the problem of object matching. More particularly, the problem of object matching entails the matching of two specific objects, for instance an object and a receipt, or two different objects such as disk reader and computer. In conventional RFID technology, merely a single tag can be used to track an object. Yet, at least two objects must be tracked in a matching relationship in the course of object matching.